Brown must have suffered the injury in Thursday night's third preseason game. The Mississippi State alum was running as Cleveland's second-team middle linebacker behind D'Qwell Jackson, racking up 10 tackles in three exhibitions.

Brown, an undrafted rookie, showed big-league potential at Mississippi State where he collected eight sacks and 13.5 tackles for a loss as a senior. Poor pre-draft workouts led him to go unpicked. Brown has a chance for instant playing time because Cleveland is so weak opposite Kamerion Wimbley.

With Terrance West (calf) and Glenn Winston (fitness) also out a few days, the only healthy backs at Browns camp are Isaiah Crowell and Shaun Draughn. The Browns may sign a free agent runner this week. As hamstring injuries are highly susceptible to aggravation, we'd expect the Browns to slow play Johnson's recovery. Missed practices are a concern for Johnson's 2015 playing time.

It was a tough practice for Cleveland as they lost DL Billy Winn to what looked like a bad knee injury and fellow RB Duke Johnson to a tweaked hamstring. West said he was not worried about the injury, but he may miss a few days. West is competing with Isaiah Crowell for early-down work in the Browns' backfield.